Help with new (used) raw water pump

Galvez83

Seaman Apprentice
Joined
Oct 31, 2019
Messages
32
I have an OMC 1998 Four Winns 5.8l ford efi that had crank mounted raw water pump. The issue was that the previous owner had a two groove pulley system for the crank and the engine water pump. That needed to be replaced for the 3 grooved pulled for water pump and crankcase. This led to the problem that the old crankcase water pump would not fit due to the new pulley. After digging i found that this engine would be allowed to have two types. The belt driven one and the crankcase one. I purchased a belt driven one (used) and replaced the impeller with new one. The issue now is the engine will not circulate water. I swapped hoses around and even sicked on the inlet hose and water is pulled up. Once it is attached to the pump it does not circulate. I read that inlet is 1 1/4 inches and outlet is 1 inch. At this point i am scratching my head. Any thoughts or ideas would be appreciated. Engine number is 58faprjvn.
 

Grub54891

Rear Admiral
Joined
Jun 17, 2012
Messages
4,578
Its possible the seals on the pump are pulling air past them. We had one at the shop that even though the pump looked good, it would not pump water. Was going to check out the seals but the owner opted for a new pump. Problem solved.
 

Lou C

Admiral
Joined
Nov 10, 2002
Messages
6,800
Agreed it could be seals, the same thing can happen with the impeller for the dog clutch Cobras that is mounted in the upper gear housing of the drive. If the o ring seal is not installed right in the groove it will suck air when the boat's on plane. I started using OMC/Evinrude triple guard grease to hold that seal in place because they tend to move when you install the housing. Then make sure there are no water leaks from the housing because if water leaks out air can also be pulled in.
 

Galvez83

Seaman Apprentice
Joined
Oct 31, 2019
Messages
32
I recently tested the raw water pump with a vacuum gauge and it holds. The impeller is new but still no water circulation. Water is pulled up to the back of the engine but circ pump not moving it around :grumpy::grumpy::grumpy:
 

Scott Danforth

Grumpy old guy who plays with boats
Joined
Jul 23, 2011
Messages
33,377
how are you supplying water to the system - muffs or boat in the water?

a bucket will never work
 

Galvez83

Seaman Apprentice
Joined
Oct 31, 2019
Messages
32
With muff was working fine with the crank mounted one. The new belt driven is the one causing issues.
 

Lou C

Admiral
Joined
Nov 10, 2002
Messages
6,800
Something in your description is not right. There was no 5.8 offered in '97 or '98 and your model number converts to a 1993 5.8 with the dog clutch Cobra using the impeller in the drive, which is obviously not what you have.

https://www.crowleymarine.com/johnso...cfm?mdl=N1AOZG
this is the part breakdown for a 58FAPRJVN

Post up some pix of what you have. If its a 5.8 Ford with an engine or crank mounted pump, it has to be a '94 or a '95 power package.


This is what you appear to have.....

https://www.crowleymarine.com/johnso...cfm?mdl=NCTQSV

There are also catalogs on the Evinrude website, but you have to go in an select 'sterndrive' then year, engine size etc.

BTW the same engine package was also sold by Volvo during that joint venture era. So whatever parts work on the Volvo should work for you, I have found sometimes that OMC/BRP will list a certain part as NLA but Volvo still stocks it, same part.
When I converted my old OMC batwing exhaust to the 2 piece manifold/elbow set up I had to get the 90* 4" to 3.5" exhaust pipes and hoses etc from Volvo because BRP no longer stocks them but the parts are all identical.
 
Last edited:

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
29,282
Buy a new water pump. Too critical of a part to go with used. I know they are expensive, but guess what, boating is expensive.
 
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